Complex regional pain syndrome: A review

Abstract

Complex regional pain syndrome (CRPS), formerly known as "reflex sympathetic dystrophy," is a chronic neurological disorder characterized by disabling pain, swelling, vasomotor instability, sudomotor abnormality, and impairment of motor function. The disorder usually develops after minor trauma or surgery. No specific diagnostic test is available and, hence, diagnosis is based mainly on history, clinical examination, and supportive laboratory findings. This review gives a synopsis of CRPS and discusses the principles of management based on the limited available literature in the area. A literature search was conducted using electronic bibliographic databases (Medline, Embase, Pubmed, CENTRAL) from 1970 to 2006. Keywords complex regional pain syndrome, reflex sympathetic dystrophy, neuropathic pain, and causalgia were used for the search. Relevant articles from the reference lists in retrieved articles were also studied. There were 3,771 articles published in the area. Seventy-six randomized controlled trials were identified. Most studies were on the role of sympathetic blockade in the treatment of CRPS (n = 13). The role of sympathectomy is unclear, with some studies showing transient benefit and others showing no beneficial effects, with most studies containing only a small number of patients. Nine studies were on bisphosphonates or calcitonin. Studies involving bisphosphonates showed benefit, but studies involving calcitonin showed no definite benefit. Four studies were on cognitive behavioral therapy, physiotherapy, or occupational therapy, all of which demonstrated a potential beneficial effect. Three studies on spinal cord stimulation and two studies each on acupuncture, vitamin C, and steroid all showed a potential beneficial effect in pain reduction. The remaining studies were on miscellanous therapy or combination therapy, making it difficult to draw any conclusions on the effect of treatment. There is very little good evidence in the literature to guide treatment of CRPS. Early recognition and a multidisciplinary approach to management seems important in obtaining a good outcome. Treatments aimed at pain reduction and rehabilitation of limb function form the mainstay of therapy. Comorbidities, such as depression and anxiety, should be treated concurrently.